There's an annual "consolidated tax certificate (CTC)" that gets generated, you'll receive an email with a subject like "IG Income Statement" when it is ready to view (last year I received mine in July).
The email contains instructions to view:
1. Log in to My IG
2. Click ’live accounts’
3. Choose your account from the dropdown
4. Select ’statements’ and choose Annual in the Period drop down options
Your tax certificate is called 2021.